There already exist so-called "video-conference" installations which are specialized intercommunication systems that can be called "multimedia" systems insofar as they transmit booth voice and animated images, and they are generally used in a single building between two conference rooms specially equipped for this purpose.
These known installations are of very limited use since they require users thereof to go to specialized video conference rooms, whereas it would be a great deal more practical for said users to be able to engage in multimedia dialog with other parties without having to leave their own offices.
One solution would be to provide an entire system specialized for this purpose, which would require each office to be equipped with a complete and specially adapted multimedia terminal. Although, a priori, such a solution is technically very satisfactory, it has the drawback of being extremely expensive both to implement and to run since it would require a special terminal complete with its own keyboard and screen to be installed in each office, whereas such an office is generally already fitted with a microcomputer, workstation, or the like, which also has a keyboard and a screen, so that it naturally appears desirable to use said keyboard and said screen for multimedia intercommunication without having to provide another keyboard and screen especially for this purpose.
Unfortunately, the use of such microcomputer or "PC" type workstations for multimedia intercommunication is, a priori, not possible. This is because:
all such workstations are not necessarily mutually compatible, either in terms of hardware or in terms of software; and PA1 the central units fitted in such workstations and the networks to which they are connected are not generally suitable for transmitting animated images, since such images require much too great a bit rate.
The invention seeks to solve these difficulties, and it thus proposes a multimedia intercommunications installation having, in particular, the capability of transmitting and receiving animated images, while nevertheless making it possible to use the screen and possibly also the keyboard or other writing means that is normally to be found in each commonplace personal workstation of the "PC" or microcomputer type.